US3619467A - Electric arc furnace and method of protecting the refractory lining thereof - Google Patents

Electric arc furnace and method of protecting the refractory lining thereof Download PDF

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Publication number
US3619467A
US3619467A US31201A US3619467DA US3619467A US 3619467 A US3619467 A US 3619467A US 31201 A US31201 A US 31201A US 3619467D A US3619467D A US 3619467DA US 3619467 A US3619467 A US 3619467A
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United States
Prior art keywords
furnace
lining
refractory
flare
pieces
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Expired - Lifetime
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US31201A
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English (en)
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Daniel J Goodman
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Individual
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    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21C—PROCESSING OF PIG-IRON, e.g. REFINING, MANUFACTURE OF WROUGHT-IRON OR STEEL; TREATMENT IN MOLTEN STATE OF FERROUS ALLOYS
    • C21C5/00—Manufacture of carbon-steel, e.g. plain mild steel, medium carbon steel or cast steel or stainless steel
    • C21C5/52—Manufacture of steel in electric furnaces
    • C21C5/5211—Manufacture of steel in electric furnaces in an alternating current [AC] electric arc furnace
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F27—FURNACES; KILNS; OVENS; RETORTS
    • F27B—FURNACES, KILNS, OVENS, OR RETORTS IN GENERAL; OPEN SINTERING OR LIKE APPARATUS
    • F27B3/00—Hearth-type furnaces, e.g. of reverberatory type; Tank furnaces
    • F27B3/08—Hearth-type furnaces, e.g. of reverberatory type; Tank furnaces heated electrically, with or without any other source of heat
    • F27B3/085—Arc furnaces
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F27—FURNACES; KILNS; OVENS; RETORTS
    • F27D—DETAILS OR ACCESSORIES OF FURNACES, KILNS, OVENS, OR RETORTS, IN SO FAR AS THEY ARE OF KINDS OCCURRING IN MORE THAN ONE KIND OF FURNACE
    • F27D1/00—Casings; Linings; Walls; Roofs
    • F27D1/16—Making or repairing linings increasing the durability of linings or breaking away linings
    • F27D1/1678—Increasing the durability of linings; Means for protecting
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F27—FURNACES; KILNS; OVENS; RETORTS
    • F27D—DETAILS OR ACCESSORIES OF FURNACES, KILNS, OVENS, OR RETORTS, IN SO FAR AS THEY ARE OF KINDS OCCURRING IN MORE THAN ONE KIND OF FURNACE
    • F27D11/00—Arrangement of elements for electric heating in or on furnaces
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
    • Y02P10/00—Technologies related to metal processing
    • Y02P10/20—Recycling

Definitions

  • the furnace between the electromagnets flux and the furnace lining at the damaging arc flare are preferably [51] lnt.Cl........& [50] Field ofSearch................................
  • FIG. 1 is a diagrammatic central vertical section through an electric arc steel-making furnace, according to one form of the invention, with the electric arc flare shown by dashed lines in the flare zone from the lower end portions of the electrodes;
  • FIG. 2 is a horizontal section taken along the line 2--2 in FIG. 1;
  • FIG. 3 is a fragmentary vertical section similar to the lefthand side of FIG. 1, but taken through a conventional steelmaking furnace fired by fossil fuel and showing the magnet arrangements as applied to a nonelectric arc furnace.
  • FIGS. 1 and 2 show an electric arc Steelmaking furnace, generally designated 10, according to one form of the invention, wherein the furnace 10 has an external steel shell 11 including a cylindrical sidewall 12 and a bottom wall 14.
  • the furnace 10 is provided with a refractory lining 16 having a sidewall portion 18 and a bottom wall portion 20.
  • the sidewall 12 and bottom wall 14 are or-' dinarily of steel.
  • a cover or roof 22 also of heat-resistant refractory material or refractory-lined material is removably mounted on the top of the furnace 10 and is provided with circumferentially spaced openings 24, preferably three in number, through which electrodes 26 project downward into the internal chamber 28 of the furnace 10 toward the hearth 29 in the lower portion thereof.
  • the electrodes 26 are also preferably three in number (FIG. 2) and are individually attached to arms 30 extending horizontally to a vertical mast 32 (only one arm and one mast being shown in FIG. 1).
  • the arms 30 together with their respective electrodes 26 may be raised and lowered by conventional hydraulic pistons and cylinders (not shown) attached to their respective masts 32.
  • the cover or roof 22 is also provided with conventional raising, lowering and swinging mechanism likewise connected to a mast (not shown), such features being well known to those skilled in the steel-making art and hence requiring no description.
  • Connected to each electrode 26 is a conventional cable (not shown) generally of water-cooled construction and running to a conventional three-phase arc furnace transformer (also not shown).
  • the furnace I is supported on pillars 34 extending downward from the bottom wall 14 thereof.
  • This flare zone is so called because of the fact that during the operation of the furnace an electric arc extending from the lower ends 40 of the electrodes 26 to the slag layer 42 and molten steel bath 44 also emits intense heat indicated by arrows 46 in FIG. I, by radiation and convection, which falls most damagingly upon the nearest portions of the sidewall lining portion 18.
  • each bore 36 is a pellet feed funnel 48 above which is a pellet feed conduit 50 communicating with a pellet hopper (not shown) which in turn is continuously supplied with iron ore pellets or fragments of ferrous metal during operation, such as by a suitable conventional conveyor (not shown).
  • a pellet feed conduit 50 communicating with a pellet hopper (not shown) which in turn is continuously supplied with iron ore pellets or fragments of ferrous metal during operation, such as by a suitable conventional conveyor (not shown).
  • Each electromagnet 52 Arranged adjacent the furnace sidewall 12 in line with the flare zone 38 from each electrode 26 is a powerful electromagnet 52.
  • Each electromagnet 52 has an arcuate iron core 54 provided with pole pieces 56, each having a winding 58 connected to flexible conductors 60 and 62.
  • the sidewall 12 is preferably cut away so that the magnetic flux from the poles 56 extends most powerfully through the nonmagnetic refractory sidewall lining I8 without being seriously diverted.
  • conventional electric power current controllers 64 are interposed between the electric conductors 60 and 62 and the electric power lines 66 and 68 leading to a source of electric power current (not shown).
  • electrodes 26 and the roof 22 are swung to one side temporarily while a charge of scrap ferrous metal is inserted in the bottom of the chamber 28 above the hearth 29.
  • the roof 22 and electrodes 26 are then swung back into their operating positions and the electrodes 26 lowered until their lower ends 40 lie adjacent the charge in the hearth 29 of the furnace 10.
  • Electric current is then caused to flow through the electrodes 26 from the transfonner (not shown), causing arcs to be struck between the electrodes 26 and the charge in the furnace 10.
  • electric current is supplied through the lines 60 to the magnets 52.
  • the intense heat emitted from these arcs reduces the furnace charge to a molten state in which a layer of slag 42 from impurities in the charge floats upon the molten steel bath 44. A part of this heat from the arcs is reflected off the surface of the slag layer 42, but the ferrous material layer 72 formed by the ferrous metal pieces 70 magnetically held against the refractory lining l8 protects that lining in the manner described below.
  • the operator delivers pieces 70 of magnetically attracted ferrous material, such as ferrous metal particles or fragments or ferrous ore pellets to the conduits 50 to the feed funnels 48, whence they fall in a shower past the sidewall lining portions 18 within the flare zone 38. Here they are captured by the intense magnetic flux flowing through the sidewall lining portion 18 and are caused to temporarily adhere thereto.
  • the pieces 70 thus collectively form a-temporary protective layer 72 or shield which receives the high-intensity arc radiation within the flare zone 38 from the electrodes 26.
  • the ferrous material pieces 70 are heated to a temperature corresponding to the so-called Curie point of about 700 C., they lose their capability of being magnetically attracted and drop through the slag layer 42 into the molten steel bath 44, adding their volume thereto.
  • a steel-making furnace is fired by fossil fuel extending through holes 84 and 86 in the shell 88 and refractory lining 90.
  • Vertically spaced electromagnets 92 mounted on the furnace 80 and having pole pieces 94 extending through the furnace shell 88 to the refractory lining are energized by windings 96 likewise connected to a suitable source of electric current by way of current controllers as shown in FIGS. 1 and 2.
  • the operator shuts off the current from the windings 86 of the electromagnets 82, causing the ferrous material pieces 98 to fall under the force of gravity.
  • ferrous material as used in the claims herein includes prereduced ferrous ore in the form of pellets, briquettes or lumps, and also includes fragmentized scrap as a full or partial substitution for conventional scrap. It will also be understood that the ferrous metal pieces, rather than being fed through holes in the roof of the furnace may, in the alternative, be fed through holes in the sidewall of the furnace, or blown through such holes or slots.
  • a refractory-protecting electric arc steel-making furnace comprising a steel-making furnace structure including an outer shell and a refractory lining therein defining a steel-making chamber, said lining including a sidewall portion,
  • said electrodes when energized emitting electric heatgenerating arcs extending downward to the ferrous material charge in said chamber and also emitting laterally extending heat flare against flare-zone areas on said sidewall portion of said lining nearest said electrodes,
  • a refractory-protecting electric arc steel-making furnace according to claim 1, wherein a furnace roof is removably mounted on said furnace structure, and wherein said feeding means is installed in said roof.
  • a refractory-protecting electric arc steel-making furnace according to claim 1, wherein said magnetic flux-generating means includes electromagnets having magnetic poles disposed adjacent said sidewall portion of said refractory lining, and also includes magnet windings adapted to be connected to a source of electric power current.
  • a refractory-protecting electric arc steel-making furnace according to claim 3, wherein said electromagnets are disposed adjacent said flare-zone areas of said sidewall portion of said refractory lining.
  • a refractory-protecting electric arc steel-making furnace according to claim 1, wherein said furnace structure shell has openings therein adjacent said flare-zone areas of said refractory lining and wherein said poles of said electromagnets extend through said openings and adjacent said refractory lining.
  • a refractory-protecting electric arc steel-making furnace wherein said roof has bores therein disposed adjacent the periphery thereof, and wherein said feeding means includes conduits extending through said bores adjacent said sidewall portion of said refractory lining above said flare zones thereof.
  • a refractory-protecting electric arc steel-making furnace according to claim 3, wherein means is provided for adjusting the intensit of magnetic flux emitted by said electromagnets.
  • a heat-resistant lining-protecting melting furnace for ferrous materials comprising a ferrous material melting furnace structure including an outer shell and a heat-resistant protective lining therein defining a melting chamber, heating means associated with said furnace structure and constructed and arranged to project heat onto a ferrous material charge in said chamber and melt said charge,
  • a heat-resistant lining-protecting melting furnace for ferrous materials wherein said magnetic flux-generating means includes electromagnets having magnetic poles disposed adjacent said sidewall portion of said protective lining and also includes magnet windings adapted to be connected to a source of electric power current and further includes electric current controlling means interposed between said magnet windings and the source of electric power current for varying the strength of the magnetic flux.

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Manufacturing & Machinery (AREA)
  • Materials Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Vertical, Hearth, Or Arc Furnaces (AREA)
US31201A 1970-04-23 1970-04-23 Electric arc furnace and method of protecting the refractory lining thereof Expired - Lifetime US3619467A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US3120170A 1970-04-23 1970-04-23

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US3619467A true US3619467A (en) 1971-11-09

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US31201A Expired - Lifetime US3619467A (en) 1970-04-23 1970-04-23 Electric arc furnace and method of protecting the refractory lining thereof

Country Status (5)

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US (1) US3619467A (de)
JP (1) JPS5127003B1 (de)
CA (1) CA939714A (de)
DE (1) DE2119692C3 (de)
ES (1) ES390529A1 (de)

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3804969A (en) * 1972-12-19 1974-04-16 Cities Service Co Elimination of side wall erosion in electric furnaces
US3832478A (en) * 1973-12-05 1974-08-27 Bethlehem Steel Corp Method for preventing early damage to furnace refractory shapes
US3883677A (en) * 1973-04-05 1975-05-13 Asea Ab Electric arc furnace having side-wall lining protection
US3885082A (en) * 1973-04-19 1975-05-20 Asea Ab Electric arc furnace side-wall protection arrangement
US3984617A (en) * 1974-03-10 1976-10-05 Allmanna Svenska Elektriska Aktiebolaget Electric arc furnace
US4122295A (en) * 1976-01-17 1978-10-24 Ishikawajima-Harima Jukogyo Kabushiki Kaisha Furnace wall structure capable of tolerating high heat load for use in electric arc furnace

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
AT389711B (de) * 1988-04-08 1990-01-25 Voest Alpine Stahl Donawitz Verfahren zum chargieren von roheisen, sowie vorrichtung zur durchfuehrung dieses verfahrens
FR2681937A3 (en) * 1991-09-30 1993-04-02 Irsid Device for continuously loading metallic products in loose form into a metallurgical furnace and metallurgical furnace equipped with a loading device

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3190626A (en) * 1962-10-01 1965-06-22 Union Carbide Corp Support means for a refractory lined furnace
US3213178A (en) * 1962-08-10 1965-10-19 Elektrokemisk As Process of charging and exhausting gas from electric smelting furnaces

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3213178A (en) * 1962-08-10 1965-10-19 Elektrokemisk As Process of charging and exhausting gas from electric smelting furnaces
US3190626A (en) * 1962-10-01 1965-06-22 Union Carbide Corp Support means for a refractory lined furnace

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3804969A (en) * 1972-12-19 1974-04-16 Cities Service Co Elimination of side wall erosion in electric furnaces
US3883677A (en) * 1973-04-05 1975-05-13 Asea Ab Electric arc furnace having side-wall lining protection
US3885082A (en) * 1973-04-19 1975-05-20 Asea Ab Electric arc furnace side-wall protection arrangement
US3832478A (en) * 1973-12-05 1974-08-27 Bethlehem Steel Corp Method for preventing early damage to furnace refractory shapes
US3984617A (en) * 1974-03-10 1976-10-05 Allmanna Svenska Elektriska Aktiebolaget Electric arc furnace
US4122295A (en) * 1976-01-17 1978-10-24 Ishikawajima-Harima Jukogyo Kabushiki Kaisha Furnace wall structure capable of tolerating high heat load for use in electric arc furnace

Also Published As

Publication number Publication date
DE2119692A1 (de) 1971-11-04
CA939714A (en) 1974-01-08
ES390529A1 (es) 1973-07-01
JPS5127003B1 (de) 1976-08-10
DE2119692C3 (de) 1974-11-14
DE2119692B2 (de) 1974-04-11

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